| 摘要 |
PURPOSE:To keep the secrecy and safety of information and to enable the replacement and rearrangement of information by providing a part which is writable only once and a part which is erasable and writable to one optical card. CONSTITUTION:The substrate 1 of the optical card is formed with a hard resin such as polyester. The left part 3 of the card is formed with a one-writing optical recording material such as Ag which can be melted by a light beam, and an information pit is bored by the melting. The part is formed by masking the right part 2 or the guard part 4 with aluminum-foiled glass, etc. Then the left part 3 and the guard part 4 are masked in the same way, and the part 2 which is rewritable as many times as desired by a light beam is formed with the thin film of Sn-Te-Se which is a material whose phase is changeable between a crystal phase and an amorphous phase. |
